TEA AND COFFEE. 175 



that is too strong is likely to produce nervousness and dys- 

 pepsia. Boiling the tea-leaves also brings out the tannic acid 

 that they contain, and produces bad effects. 



Coffee owes its stimulating effect to a substance called 

 Caffein, which is considered identical with thein. Coffee acts 

 as a restorative after hard labor, seeming to retard the wastes 

 of the tissues and food. It is used in the army (also in peni- 

 tentiaries), not as a luxury, but as a matter of economy in 

 the matter of food supply. Coffee, used to excess, frequently 

 causes palpitation of the heart. 



Malted and peptonized milk makes a valuable drink for in- 

 valids and dyspeptics. 



Cocoa contains a stimulant called Theobromin. But unlike 

 tea and coffee, cocoa and the preparation from cocoa known 

 as chocolate are true foods, by virtue of the fat contained. 



Beef tea and various beef extracts are very beneficial. 

 There is not enough nourishment in them to maintain strength 

 without other food. Their nutritive value has been somewhat 

 over-estimated. Their value is as much, if not more, in their 

 stimulating as in their nourishing effect. But many of the 

 soups and drinks made from these preparations are very bene- 

 ficial. They refresh the tired system wonderfully. Many a 

 man who takes a drink of liquor to " brace him up," as he 

 says, would do far better to take a cup of hot bouillon. He 

 would find himself braced up for the time, without any bad 

 reaction, or permanent injury to the system. 



Alcohol. Alcohol is not a food. But because it is taken 

 into the digestive tube, and produces its effects primarily 

 through the digestive system, it is here presented. 



If we eat a sufficient amount of bread to-day, we do not 

 crave a larger amount to-morrow ; but the appetite for alco- 

 hol grows ; the law of its use is the law of increase, until the 

 terrible alcohol habit is formed. 



